There are three major objectives of this research, all of which relate to the general objective of learning more about the effects of early deprivation in primates. The first objective is to determine and to define the initial status, the growth, the development, and the adaptive capacity of infant monkeys born of mothers fed different levels of protein during pregnancy. The second major objective is to study maternal-fetal interactions in determining the course of pregnancy, with a view toward identifying fetal distress. The third major objective is to produce during the period of the grant a group of infant rhesus monkeys born of mothers fed 1, 2, or 4 grams of protein per kilogram of body weight per day during pregnancy and who are maintained on diets inadequate in protein during the first 120 days of postnatal life. These animals will be examined and tested in a manner comparable to those whose undernutrition was confined to the prenatal period only. Biochemical, osteological, urological, physiological, and behavioral examination will be conducted. BIBLIOGRAPHIC REFERENCES: Riopelle, A.J., and Shell, W. F., Protein deprivation in primates. IX. Determinants of weight change during and after pregnancy. Submitted. Riopelle, A.J., Reply to Dr. Jacobson. Am. J. Clin. Nutri., 1975, 28: 802-804.